ROHM Unveils Ultra Low Ohmic Chip Resistors for Automotive, Consumer, and Industrial Equipments

ROHM Unveils Ultra Low Ohmic Chip Resistors for Automotive, Consumer, and Industrial Equipments

ROHM has added three new products featuring a rated power of 5 W in resistance values of 0.5 milli-ohm, 1.0 milli-ohm, and 1.5 milli-ohm to the 2512-size (0.25 inch × 0.12 inch) / 6432-size (6.4 mm × 3.2 mm) PMR100 series of standard type metal plate shunt resistors designed for motor control and power circuits in automotive, consumer, and industrial equipment applications.

Shunt resistors for current detection are primarily used for power supply overcurrent protection, battery level detection, and in motor drive circuits in a wide range of fields, including the automotive, industrial equipment, and consumer electronics sectors. To achieve power savings required for various applications, precise circuit control using high accuracy high-reliability shunt resistors is necessary. On top, as application functionality improves, boards are becoming denser, requiring smaller, higher-power shunt resistors. Particularly in the automotive field, it is important to ensure high detection accuracy even under high-temperature environments.

These new products achieve a rated power of 5 W by utilizing new materials with excellent temperature characteristics and terminal temperature derating. This represents the best-in-class for 6432-size flat chip types with protective film. Achieving approx. 2.5 times higher rated power than conventional PMR100 2 W products and around 1.7 times higher than 3 W models makes it possible to replace larger high-power types - contributing to greater miniaturization in a variety of applications. Additionally, a rated terminal temperature of 130°C (for 0.5 milli-ohm and 1 milli-ohm products) and operating temperature range from -65°C to +175°C are guaranteed, ensuring stable operation even in extreme temperature environments. An excellent temperature coefficient of resistance (TCR) of ±75ppm/°C enables reliable, high-accuracy current detection.

ROHM continues to advance the development of resistors. By further increasing the power and resistance ranges, ROHM can expand the PMR100 series to include compact, high power, high temperature, high accuracy models as well as 4W types in the smaller 1210-size (0.12 inch × 0.1 inch) / 3225-size (3.2 mm × 2.5 mm) and 2010-size (0.2 inch × 0.1 inch) / 5025-size (5.0 mm × 2.5 mm).

Key applications

  • Automotive: EPS, electric compressors, oil/water pumps, door motors, ADAS controllers, etc.
  • Industrial Equipment: Industrial power modules, power conditioners, power tools, PV inverters, server power supplies, UPS (Uninterruptible Power Supplies), base station power supplies, etc.
  • Consumer applications: Home appliances (e.g. Air conditioners, refrigerators, vacuum cleaners, washing machines), etc.